One situation which requires the use of trocars, is laparoscopic tubal cauterization where CO.sub.2 is insufflated into the abdominal cavity of a patient under anesthesia. The trocar, consisting principally of a sharp-pointed puncturing instrument fitted with a cannula, pierces the body cavity whereafter the puncturing element is withdrawn leaving the hollow cannula in place to receive a laparoscope for examination of the abdominal cavity. Further explanation of the cauterization procedure as well as of a novel instrument therefor may be found in Canadian patent application Ser. No. 175,625 filed July 4, 1973 in the name of Jacques Rioux et al.
Present trocars used in this type of surgical act are made of metal and, consequently, must be cleaned and sterilized after each use. Hence, there is need for a disposable trocar which is simple and inexpensive and which will perform just as efficiently as the present metallic trocar.
Some disposable trocars exist; however, none are constructed so that they may be used for laparoscopic tubal cauterization. Most are designed primarily for allowing the passage of fluids to and from the body cavity. For use with laparoscopic tubal cauterization, the trocar must be structured to prevent any leak of CO.sub.2 which is under pressure (about 5 p.s.i.) inside the abdominal cavity. It is essential that the abdomen remain insufflated during the entire procedure to allow the surgeon to clearly see and to freely work inside the cavity.